Studies of magnetic nanoparticles Mn$_x$Fe$_{3-x}$O$_4$@OA (0 $\le x\le$ 1.0) functionalized with oleic acid (OA) for biomedical applications

Functionalization of magnetic nanoparticles (MNP) is a unique of magnetic nanoparticles (MNP) is a unique tool for creating particles with the properties required for biomedical applications. Therefore, the study of the magnetic properties of coated MNPs is the most important task of our time. The effect of changes in the concentration of Mn ions on the properties of Mn$_x$Fe$_{3-x}$O$_4$ nanoparticles coated with oleic acid (OA) Mn$_x$Fe$_{3-x}$O$_4$@OA (where $x$ = 0, 0.25, 0.5, 0.75 and 1.0) to create stabilized magnetic fluids for various applications is investigated. The synthesis of Mn$_x$Fe$_{3-x}$O$_4$@OA MNPs was carried out by thermal decomposition using manganese-oleate and iron oleate. The properties and phase states of the obtained MNPs were studied by X-ray diffraction (XRD) and Mossbauer spectroscopy. To understand the behavior of MNPs in small magnetic fields during hyperthermic treatment, Mossbauer studies of Mn$_x$Fe$_{3-x}$O$_4$@OA particles were carried out when a magnetic field with a strength of 1.7 kOe was applied. It is established that the thermal decomposition method makes it possible to obtain single-phase superparamagnetic particles promising for biomedical applications